Natural Remedies in the Fight Against Parasites

chemical defence against fungi, phytopathogens, birds, and other natural predators, being also

used by plants to attract pollinators as well, being indispensable to guarantee plant’s survival

and its spreading through the globe. However, human population takes advantage of these

remarkable properties and uses some compounds produced by diverse organisms including

plants, fungi, and sponges to develop new medicines. Those metabolites coming from natural

sources will promote the desirable healing action, bringing fewer side effects to the users.

In addition to teas, infusions, plasters, and herbal medicines, many traditional “western

drugs” that are widely used nowadays had its origins on medicinal plants, such as (1) aspirin

(acetylsalicylic acid—Spiraea spp.), (2) artemisinin (sweet wormwood—Artemisia annua), and

more recently, (3) taxol (or paclitaxel from Pacific yew—Taxus brevifolia) on Figure 1 can exem-

plify [ 2 ]. Therefore, nature is an endless source of bioactive substances, as plants can convert

just carbon dioxide and water through photosynthesis to produce highly complex organic

molecules that could be very useful in human health.

Medicinal plant species constitute a valuable alternative to conventional medicine in many

developing countries; especially in poor communities that inhabit rural areas, lacking access

to health services. Several of them use plants as the primary health care, as teas, plasters, infu-

sions, and ointments among others. The traditional use of medicinal plants and natural rem-

edies with no established efficacy and safety is a widespread in many countries around the

world. Accordingly, all the information about ethnobotany is of utmost importance: this kind

of millenary knowledge built during centuries usually combines information from native

indigenous culture, together with acquirements brought by the Europeans and the Africans

and provides a more rational use for the local biodiversity.

In other hand, protozoan diseases represent an important health threat in countries of tropical

and subtropical regions, causing mortality to their populations [ 3 ]. Many neglected tropical

diseases (NTDs) transmitted by parasites are reported to have life cycles including man as

a secondary host, in which they cause disease. About 37 million individuals are presently

Figure 1. Important drugs from medicinal plants: aspirin (1), artemisinin (2), and taxol (3).

94 Natural Remedies in the Fight Against Parasites